Kate Mara and Clark Gregg have joined Marvel Studios’ Iron Man 2, being directed by Jon Favreau and currently shooting in Manhattan Beach, California.

Mara’s role is being kept under wraps, while Gregg is returning as Agent Phil Coulson of S.H.I.E.L.D.

The duo joins a cast that includes Robert Downey Jr., Gwyneth Paltrow, Don Cheadle, Jon Favreau, Mickey Rourke, Sam Rockwell, Samuel L. Jackson, Scarlett Johansson, Garry Shandling and John Slattery.

Paramount will release the sequel in theaters on May 7, 2010.